unset() to destroy variable in PHP

Remove variables or array elements with unset()

unset() removes a variable or selected array element. Removing an array element does not automatically reindex numeric keys; use array_values() when a consecutive numeric index is required afterward.

<?php
$items = ['red', 'green', 'blue'];
unset($items[1]);
$items = array_values($items);
print_r($items);
?>

We can destroy variable by using unset function.

Unset(variable)

Here is an example.

$my_var='plus2net';
echo " before unset : ".$my_var;
echo "<br>";
unset($my_var);
echo "after unset : " .$my_var;

The output is here

before unset : plus2net
after unset  :

Unset function will remove local variable only. For example it can remove only variable inside the function and it does not affect outside the function. Here is one example to understand how unset function work inside function.

$my_var='plus2net';

function unset_var()
{
global $my_var;
echo "Before unset and inside function :".$my_var."<br>";
unset($my_var);
echo "after unset and inside function  :".$my_var."<br>";
}
echo "Outside function before using function : ".$my_var."<br>";
unset_var();
echo "Outside function after using function : ".$my_var."<br>";

Here is the output

Outside function before using function : plus2net
Before unset and inside function :plus2net
after unset and inside function :
Outside function after using function : plus2net

Declaring variables Cookies to store Infomation Getting Type of Variable var_dump() isset() empty()

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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unset(): removes a variable from memory

Remove variables or array elements with unset()

Subhendu Mohapatra